Road-tamping machine



A g- 1929. E. H. CARLSSON ROAD TAMPING MACHINE 4 Sheets-Sheet l Filed Jan. 8, 1929 E. H. CARLSSON ROAD TAMPING MACHINE Filed Jan. 8, 1929 4 Sheets-Sheet 2 w a n n a a M ,1 #1 M M f 2 1929- E. H. CARLSSON ROAD TAMPING MACHINE Filed Jan. 8, 1929 4 Sheets-Sheet 3 g- 1929. E. H. CARLSSON ROAD TAMPING MACHINE 4 t e e h S s t e e h S 4 Filed Jan. 1929 Patented Aug. 20, 1929.

UNITED STATES ERNST HJ'ALMAB CARLSSON, OF TANNEFOIBS, LINKOPING, SWEDEN.

ROAD-TAMPING MACHINE.

Application filed January 8, 1929, Serial No. 331,011. and in Sweden December 31, 1927.

This invention relates to an improved machine for compressing and tamping streets and roads paved with gravel, road-metal or other paving material, said machine being adapted to be used instead of the road-rolling-machines hitherto used which are open to several defects or inconveniences.

According to the invent-ion, the machine is provided with an endless band or bands of the chain type driven in a suitable manner and cooperating with the road, said band being connected with lifting means in such a way that the part thereof cooperating with the road is momentarily lifted from the road and then dropped upon the same, the road being thereby subjected to an effective pounding or tamping treatment. The liftin means are so arranged that the lifting an droppin of the band may be effected when the mac ine is moving forward as Well as backward. The band travels between sprocket wheels or the like journaled at the front and at the rear of the frame of the machine; the rear sprocket wheels, by the action of the weight of the machine, pressing the band upon the road and rolling over said band when the machine is moving, while the front sprocket wheels are journaled in such a waythat the hand does not contact with the road at that point.

As the lifting means of the band are arranged between the front and rear sprocket wheels, the road, when the machine is moving forward, will first be effectively treated by that part of the band moving up and down, and then the road will be additionally compressed and levelled by the rear sprocket wheels rolling on the band over the treated surface. A great advantage of the machine according to this invention is, that the part of the band moving up and down is able to treat the road also when the machine is standing still.

The accompanying drawings show the preferred embodiment of the invention.

Figure 1 is a side elevation of the machine,

Fig. 2 is a plan view, partly in section, of the same,

Fig. 3 is an enlarged cross-section on the line 33 in Fig. 2,

Fig. 4: is a fragmental longitudinal section on the line 4-4 inFig. 3.

In Fig. 2, the band is partly removed, in order that the other members may appear more plainly.

able distance from the shaft 2 another transverse shaft 5 is journaled in the frame 1, to which shaft four sprocket wheels 6 likewise are keyed, said wheels being situated at the same distance from and firmly connected to each other by'supporting rollers 7 of less diameter than the sprocket wheels 6. A broad chain-band travels between the sprocket wheels 3 and 6 and consists of chain links 8 engaging the teeth 9 and 10 (Fig. 1) of the sprocket wheels 3 and 6, and of supporting links 11 cooperating with the supporting rollers 4 and 7.

Thus, the band, in its entirety, consists of seven chains situated at the side of one another, four of said chains being constituted by the links 8 engaging the sprocket wheels 3 and 6, and the three remaining chains being constituted by the supporting links 11 cooperating with the rollers 4 and 7. The band may, of course, according to circumstances, comprise a greater or less number of chains than that shown in the drawings. The links of the chains of the band are connected to each other by cross-pins 12 (Figs. 1 and 3). Two transverse shafts 13, 14 are journaled at the top of the side-pieces l of the frame, supporting rollers l5, 16 for the band being keyed to said shafts.

The two side-pieces 1 of the frame are connected with each other by two cross-pieces 17, 18 which support'means for momentarily lifting and dropping that part of the band contacting the road. For this purpose a number of separate supporting devices (in the drawings, three) situated at the same distance from each other in the transverse direction of the machine, are secured to the cross-pieces 17, 18. Each supporting device comprises bearings for two rotatable members causing the lifting of the band, and consists of four longitudinal supporting members forming an upper pair 19 and a lower pair 20, the latter pair being situated direct-g 1y below the upper pair 19. The upper members 19 are each provided with two bushes, and each lower member 20 is also provlded with two bushes in such a way that two separate bearings 21, 22 are formed (best seen in Figs. 3 and 4). y

In the bearing 21 there is arranged a 1'0- tatable member in the form of a disk 23 having a toothed circumference or rim 24 which fits between the opposite sides of the bearing and is journaled therein by means of its outer edges 25, as indicated in Fig. 3. The teeth on disk 3 are thus exposed so as to enable them to mesh with a toothed wheel 26 keyed to a shaft 27 journaled in the sidepieees 1 of the frame. The shaft 27 maybe brought into and out of driving connection with the motor by a device described below. In the other bearing 22 a secondrotatable disk 23 is journaled in the same manner and is of the same construction as the disk first described and journaled in .the bearing 21. The second disk 23 also has a. toothed rim 24 on its circumference which meshes with the rim of the disk journaled in the bearing 21.

One of the three supporting devices now has been described; the two other are of just the same construction.

Each of the disks 23 journaled in the bearings 21, 22 is provided with a diametric slot 28 which widens towards both sides at its ends as 2.9, 30 and 31, 32' (Fig. 4). A transverse rod 33 is inserted through the slots 28 of the three disks 23 journaled in the bearings 21 (Fig. 3), and a. similar rod 34 is inserted through the slots 28 of the disks journaled in the bearings 22; each rod 33 or 34 being provided at each disk 23 with a pair of depending supporting arms 35. Each pair of supporting arms 35 on the rod 33 is situated opposite a corresponding pair of arms on the rod 34 and jointed to said arms by a cross-piece 36 (Figs. 3 and 4).

The jointed connection is provided by two transverse rods 37, 38, one of which is inserted through perforations in the cross-pieces 36'and in the lower ends of all the supporting arms 35 extending downwards from the rod 33 (Fig. The other rod 38 is likewise inserted through perforations in the cross-pieces 36 and in the lower ends of the supporting arms extending from the rod 34. In each of the cross-pieces 36 there is an upper horizontal row of pins 39 and a lower horizontal row of pins 40, said pins extending in a direction transverse to the band and being journaled in the cross-pieces (Figs. 3 and 4). The cross-pieces are connected with the band in such a manner that two inner flanges 41 on each supporting link 11 extend between the upper row of pins 39 and the lower row 40. Thus, the cross-pieces are in permanent lifting engagement with that part of the band cooperating with the ground, and may be moved along the band by the pins cooperating with the flanges. As described above, each of the rotatable disks 23 is provided with a slot 28 which is widened or enlarged at its ends, and the walls of these enlargements serve as carriers for the lifting rods 33 and 34. The ends of therods 37, 38 are movable up and down in vertical guideslots 42 in the side-pieces 1 of the frame (Figs. 1 and 3). Springs 43 are placed on the inner and outer sides of the side-pieces 1 under the rods 37, 38, said spring serving to limit the downward movement of the rods 37 and 38.

As described above, the shaft '2, the sprocket wheels 3 and the rollers 4 rotate together as a unit, such unit being driven by a motor, which latter will now be described. Two worm-wheels 44 (Fig. 2) are rigidly connected either to the shaft 2 or to the two outer sprocket wheels 3, said worm-wheels being situated one adjacent each side-piece l of the frame. A worm 45, secured to a horizontal longitudinal shaft 46, engages each worm-wheel, said shaft being journaled in the corresponding side-piece 1 (Fig. 2).

'A coupling or clutch comprising fast and loose members 47 and 48 is mounted on each shaft 46 and in order to bring the fast clutch members 47, which are keyed to the shaft, into and out of coupling engagement with the loose members 48, a transverse horizontal shaft 49 is journaled in two bearings 50 at the bottom of the frame (Figs. 1 and 2). At each end, directly below the fast clutch members 47 this shaft 49 is provided with an upstanding pin 51 (Fig. 1) engaged in an annular groove 52 in the corresponding fast coupling member 47. An upstanding lever 53 is secured to the shaft 49, and by means of which the shaft may be rotated in one or the other direction. Rigidly connected to each of the loose coupling members 48 is a toothed wheel 54 also loosely mounted on the shaft 46, and rigidly connected to a' sprocket wheel 56 by means of a hub 55, said sprocket wheel being also loosely mounted on the shaft 46. The two sprocket wheels 56 are connected by chains 57 with two other sprocket wheels 58 secured to each other and also to a rotatable shaft 59 forming part of a change-speed gear device 60 of known construction, said change-speed device being preferably built together with the motor 61 and provided with a shifting lever 62 by means of which the direction of rotation of the shaft 59 may be reversed.

The device for bringing the cross-shaft 27, to which the pinions 26 cooperating with the toothed rims 24 are keyed, into and out of driving connection with the motor 61 will now be described. A worm-wheel 63 is keyed to each end of the shaft 27 each worm-wheel engaging a worm 64 secured to a horizontal longitudinal shaft 65 journaled in the frame of the machine (Figs. 1 and 2). Each wormshaft is provided with a coupling device or clutch comprising fast and loose clutch members 66 and 67 the latter being attached to a toothed wheel 68 also loosely mounted on the shaft 65 and engaging the toothed wheel 54 of the corresponding shaft 46. In order to bring.the fast clutch or coupling members 66 into and out of en agement with the loose coupling members 6 there is provided a transverse horizontal shaft 69 journaled in two bearings 70 at the bottom of the frame; and said shaft likewise carries at each end, directly below the fast coupling members 66, an upright pin 71 (Fig. 1) that engages in an annular groove 72 1n the corresponding coupling member 66. An upright lever 73 is secured to the shaft 69 and serves to rotate the same in one or the other direction.

A levelling roller 74 is journaled at one .end of the frame, and at the other end there are two guiding rollers 75 of suitable construction.

The operation of the machine will now be described :-lVhen the shifting lever 62 occupies the position indicated in full lines in Figs. 1 and 2, the motor 61. is disconnected and the shaft 59 is standing still. By swinging the lever 62 to the right, the shaft 59 is caused to rotate in one direction, and by swinging the lever to the left said shaft is caused to rotate in the opposite direction. Thus, when the lever 62 is swung to the left or to the right, the shaft 59 is caused to rotate, so that the sprocket wheels 58 through the chains 57 rotate the sprocket wheels 56 and also the toothed wheels 54 and the coupling members 48 rigidly connected thereto. Thereby the toothed wheels 68 engaging the toothed wheels 54, and the coupling members 67 are, evidently, rotated, while the shafts 46 and 65 remain stationary. It is now possible, as desired, either to connect the sprocket wheels 3 and the supporting rollers 4, for moving the machine on the road, or to connect the driving shaft 27 of the disks 23 in order to eifeot the lifting and the dropping of that part of the band that cooperates with the road, or it is possible to connect both the sprocket wheels 3 and the driving shaft 27 to the driving source. If the lever 53 is swung to the left from the central position shown in Fig. 1, the coupling members 47 are moved into.coupling-engagement with the rotating coupling members 48 by the pins 51 on the shaft 49, the shafts 46 being thereby caused to rotate, too. In consequence, the

worms 45 rotate the worm-wheels 44 and also 1, the pins 71 "on the shaft 69 move the two coupling members 66 into coupling engagement with the rotating coupling members 67, so that the shafts 65 are caused to participate in the rotation. Hence, the worms 64 rotate the worm-wheels 63 and also the shaft 27 with the toothed wheels 26 which in turn rotate the disks 23 in their bearings 21, 22 through the toothed rims 24. The disks 23 are rotated in the directions indicated by the arrows in Fig. 4. The walls of the enlargements 29 of the slots 28, which serve as carriers for the rods 33, 34, carry these rods a proximately to the position indicated dash-dot lines in Fig. 4, so that the part of the band located thereunder and contacting with the ground, is lifted (as shown in the dash-dot lines in Fig. 4). When the rods 34, 34 have been lifted to the position indicated in Fig. 4, the same are released from the enlargements 29 and fall down through the weight of the lifted part of the band. In the meantime the enlargements 32 have reached such a position that the walls of the same contact with the rods 33, 34 and again lift these rods, and so on. Thus, during the rotation of the disks in the directions of the arrows (Fig. 4) the walls of 'the enlargements 29, 32 serve as carriers for the said rods. If the disks are rotating in the opposite direction, the walls of the enlargements 30, 31 serve as carriers.

Due to the lifting and the dropping of the heavy band, which may be done for instance 60 times a minute, the road is subjected to a very effective tamping treatment. This will be further increased by the sprocket wheels 3 with the supporting rollers 4 rolling along the band over the treated place and, by the action of the great weight of the machine, effecting an additional treatment and, above all, a levelling of the road. Finally, the roller 74 effects a subsequent levelling of any slight roughnesses remaining.

A great advantage of the machine is, that it can work in both directions, so that it may easily be repeatedly moved to and fro on the road if required, and may also be left standing while the part of the band contacting with the road works up and down, when it is desired to give some place on the road a particularly effective treatment. When the machine is to be moved between different working points, the driving means for effecting the lifting and the dropping of the band is disconnected.

Of course, instead of a single broad band 1 or chain, a number of narrow chains or bands may be used; and instead of a number of sprocket wheels rigidly connected to each other, there may be used one front sprocket wheel and one rear sprocket wheel only. Furthermore, the number of rotating disks 23 may be varied according to the strains and to the width of the band. The embodiment shown may also be altered in other respects without departing from the spirit of the invention.

v I claim as my invention 1. A road tamping machine, comprising an endless flexible tamping element, driving means therefor, and mechanism operating automatically during the travel of the machine for alternatel lifting and dropping that portion of the exible tamping element cooperating with the surface of the road.

2. A road tamping machine, according to claim 1, in which the means for driving the flexible tamping element operate reversibly to effect movement thereof in either direction of travel at Will; and in which the mechanism for lifting and dropping said. element is operative equally for both directions 0 movement of said element.

3. A road tamping machine, according to claim 1, in which the flexible tamping element comprises alternating rows of chain links and supporting links disposed side by side and connected together.

4. A road tamping machine, comprising an endless tamping element, front and rear wheels for driving said element and around which the same passes; the rear wheel acting to (press the tamping element upon the road an to roll along the same when the machme is in motion, and the front wheel being situated above the road so as to hold said tamplng element out of contact with the road at that pomt; and mechanism operating automatically during the travel of the mach ne for alternatel lifting and dropping that portion of the flexible tamping element cooperatlng with the surface of the road.

5. A road tamping machine, comprising an endless flexible tamping element, chainand-sprocket driving mechanism therefor, means inde endent of said driving mechanism for a ternately lifting and dropping that portion of the tamping element cooperatlng with the surface of the road, a motor, and coupling means for selectively connecting and disconnecting the driving mechanism and the lifting mechanism with and from the motor. a

6 A road tamping machine according to claim 5, 1n which both mechanisms may be connected to the motor at the same time, or either one only.

In witness whereof I have hereunto signed my name.

ERNST HJALMAR GARLSSON. 

